Question

What is the oxidation state of $Mn$ in $KMn{O}_4$?

• A. -7
• B. -3
• C. 7
• D. 3
• E. 0

Answer 1

Answer: (C)

Option $E$ is the correct answer.

${KMnO}_4$ dissociates as $K^{+}$ and ${MnO}_4^{-}$ . Thus we will now calculate the oxidation number of $Mn$

Let us suppose it has an oxidation state of X. Thus the equation is-

$+1$$+$ $X$ $-$ $8$ $=$ $0$

Thus the value of X is $+7$

The equation has been written in that manner because ${KMnO}_4$ has an overall oxidation number of 0. $K$ has an oxidation number of $+1$ and $O$ has an oxidation number of $-2$. Thus four oxygen atoms will have an oxidation number of $-8$

Oxidation numbers on both the sides should be balanced and hence we get the value to be +7.